Twenty Eighth International Obfuscated C Code Contest
15 comments
·August 3, 2025dbacar
_kb
That's a bit of a hat tip to donut.c: https://www.a1k0n.net/2011/07/20/donut-math.html
isoprophlex
https://www.ioccc.org/2024/stedolan/index.html
Reading last years entries, this image decompression oneliner outputs its own logo when passed the hash of its source code?! Pretty neat.
jama211
Yeah I just read that one, insane!
ForOldHack
Thank you Barry Kerchival, My C programming teacher for sharing obfuscated code, and showing us utter abuse of the C pre-processor. "This does not do what you think it does."
"Recalcitrant code."
_kb
For an obfuscation comp, I love the fact they explicitly refer to and do not rewrite "index.html web pages for each winning entry".
4pkjai
As a noob, this is confusing me.
bcardarella
> Increased submission quantity and quality
So everybody just LLM'd this, right?
AlotOfReading
I didn't find them useful when I wrote my entries. LLMs get confused with code that "looks like" other code, and that intentional misdirection is half the fun of a good IOCCC entry. Plus, the morality filters get annoying once you obfuscate the code. Plugging an unsubmitted entry into Gemini, it refuses to even explain it because it thinks it's malware.
s-macke
LLMs can help you analyze the code, but not write it. Their ability to obfuscate is quite limited and uninspired. The last IOCCC was in 2020, so we've had plenty of time to work on it.
null
mattigames
Vibe obfuscation, all the cool kids are doing it.
Disposal8433
That would be the Underhanded C Contest (https://en.wikipedia.org/wiki/Underhanded_C_Contest)
w-ll
i guess that should make vibe de-obfuscation as easy
evrennetwork
[dead]
This is epic: :)
From : https://github.com/ioccc-src/winner/blob/master/2024/kurdyuk...
This code draws the current moon phase to the console. So if you’re a lycanthrope, you can monitor the phase of the moon.
#include <time.h> #include <stdio.h>